Fuel mixer



Patented Sept. 1926. I l

UNITEDy STATES y(''ARIilCl MCKEE, OF ROCKFORD, ILLIINOIS.

FEL MIXER.

Application filed May 23,

. ingv from the maximum-capacity of the burnl ers to the minimum turn down requirements,

a mixture comprising the properproportions l.of air `and gas.

Another object 1s to provide ami'xer which will deliver at all times a highly energized mixture i. e.a mixture not only of the proper proportions, but yalso under the requisite pressure. to result in high eflicieney at the burners and minimize the'lliability of iiare backs.

.Still another and highly important object of my invention is the provision of a mixer possessing the advantages above mentioned, which can be operated from-a single control. In other words, the manipulation of a single control lever serves to regulate theA heat delivered by the burners, and since this control regulates the quantity only of the mixture delivered, any liability of delivering an ineficient mixture, either too rich or too lean, such as is apt to occur with devices in which the air and gas supplies are independently controlled, is obviated.

A further purpose of my prevent invention, therefore,is to provide an apparatus which will deliver, at all times in operation, Y

v a predetermined quantity of-air under relatively high pressure, and a sufficientpredetermined quantity o f gas, to produce a mixture of lthe requisite quantity and proportions for turn down purposes.l This mixtureis supplemented when additional fuel is required, by opening the control valve which adds to this initial mixture, any desired quantity of airand gas always in predeterminedproportions, so that the resultantv mixture delivered to the-burners is of the requisite proportions.

nother ob`ect of the invention is to provide .for regulation to a finedegree of-nicety ofthe relative proportions of airy and gas, both inthe initial and in the supplemental mixtures,"s'o thatthe' most ,efficient mixture caribe secured withthe many and various grades and characters of'gas 'employed' for industrial purposes.

- vention.

always v 1922. serial No. 563,059.'

.11.1.fri-:NTI4 OFFICE. l

Another feature of. my invention resides I in the fact that,lafter the apparatus has been set and adjustedv for any particular grade of gas, it'may beV operated to deliver the mixture in'any desired quantities by the manipulation of a single control lever, and Without varying the proportion of the mixture.

Furthermore, should` it be found that at'.l

some point in the turn down, the proportion `of gas in the mixture 'isa little too high or a little too low, such error may be rectified by a further adjustment provided for by my in- For the purpose ofi facilitating an understanding of my invention, I have illustrated on the-accompanying drawings a preferred embodiment thereof, from an inspection of which, when considered in connection with the following description, the construction, operation and inherent advantages of my invetion should be readily understoodand ap preciated.

Referring to the drawings: Fig. l is a vertical sectional view through a mixer .embodying my invention;

Fig. 2 is a fragmentary elevational view.

looking toward the yleft at Fig. 1 at the height of the air intake port;

Fig. 3` is a plan view of the mixer shown in Fig. l; and y Figs-land 5 are vertical and horizontal sectional views, taken onv thelines 4 4 and 5 5 respectively, of Fig. 1. y

Referring to the drawings, reference' character 6 indicates a fuel mixture delivery conduit, preferably of Substantially Venturishape nearits receiving end and connected I at its deliveryfend with the burners of the l apparatus to which the mixture is'delivered. lnthe form of the invention illustrated, the

receiving end of this conduit is threaded intov w a T-'itting 7, the end of this fitting opposed to the conduit 6 being closed by a -fplugS` through which projects an air supply pipe 9 the requisite pressure.

this pipeis provided with arestricted .porti` 11, through fwhich the airi under pressure is 105 To the upperside of `this'iitting there isi discharged as a jet into the conduit 6.

"connected by'a nipple 12, a 'valvey casing 13,

provided' with an vair inlet port `i4; opening to atmosphere, and a' gasfinl'eti port? 15' toI whichgasis supplied' frornal pipe 16.* In lorderto ensure'a uniform'deli'v'ery'ojf gas, ay 1 pressure regulator or reducing valve (not I connected to any suitable source of air under The delivery end of shown) is interposed in the pipe 16, so that the gas will 4always be delivered to the valve casing at a uniform pressure, preferably substantially atmospheric pressure, irrespective of pressure fluctuations in the gas supply line.

Within this casing there is rotatably mounted a proportional mixing valve 17, preferably substantially like that disclosed in my prior Patent No. 1,404,211 issued January 24, 1922. This valve is provided with a port 18 adapted to register with the port 15, and gas entering through this port is deflected downwardly toward the delivery end of the valve casing by a longitudinally disposed partition wall 19. The valve is also provided with an air intake port 21 adapted to register with the port 14, and the valve ports are so disposed in relation to the casing ports that when the valve is turned, both ports will be simultaneously opened or closed, as the case may be, substantially equal amounts to maintain a predetermined proportion between the amounts of air and gas entering the valve casing. To compensate for the diiference in shape of the air and gas inlet ports, the port 21 has its lower end formed on a curve, as indicated at 22, Fig. 2, so that as this port approaches closed position, its area is reduced proportional to the reduction inA area of the gas port 18. This reduction will be apparent from Fig. 2, wherein the position of the port when in partially closed position is show n in dotted lines.

To provide for the attainment of a desired proportion of air and gas which will be admitted by this valve, the valve is adapted to be vertically adjusted in its casing, and with this end in view, the valve body is provided with an overhanging bracket 23, by which the valve is suspended in its casing upon a bar 24 mounted upon the top of the casing 13, an adjustable set screw 25 being threaded through -the bracket 23 into en agement with the bar 24 by which the weig t of the valve is carried. A handle 26 is adjustably mounted upon the post 27 extending upwardly from the bracket 23 and a lock nut 28 serves to lock the screw1 25 in adjusted position. The handle is also locked by a set screw 29. The adjustment of the handle 26 is provided in order that an index finger 31 projectingjradially from the hub of the handle may e disposed in the requisite posif tionl over a scale 32 provided upon the top of the valve casing, which assists the operator in determining the extent of opening or closing of the valve by manipulation of the handle lever. When the valve is fully opened a lug 33 projecting downwardly from the lever 26 engages a ug 34 projecting radially from the Vcasing 13 and closingmovements of the valve may be regulated by an adjustable abutment screw 35 threaded through `a stud 36 projecting radially from the valve casing. The'valve may be locked in any desired position by a set screw 37 threaded through the lug" 33 and adapted to be clamped against the wall of' the casing.

It will be apparent that if the screw 25 is manipulated to raise the valve 17, the area of the gas inlet port 18 will be increased,

while the area of the air inlet port 21 will,

be diminished. Consequently, by adjusting the valve to the requisite height, the proper small port 38 (Fig'), and a stud or rib- 39 on the casing is provided with a series ofl ducts 41 adapted to register with the port 38 in diderent positions of the valve. These ducts may communicate at their outer ends with atmosphere through a slot 42, andr any or all of them may be closed by screws 43' threaded into the outer ends of the ducts. It', therefore, any grade of gas with which the apparatus may be used requires the admission of more air at any point in the opening or closing movements of thel valve, this additional air may be supplied by removing from one or more of the ducts 41, vits screw plug 43, and if less than the amount of air which would be admitted through one ot these ducts whenfully opened is required, the quantity may be regulated to' a line degree of nicety by adjusting its screw yplug' in the manner of a valve to admita greater or lesser vquantity of air. When gas is admitted throughthe port 18, justsutliient air is admitted simultaneously throughl he proportional mixing valve to produce a mixture of the requisite proportions.

Gas in proportion to the amount of air under pressure delivered through the jet orifice 11 is admitted independently o f thereontrol valve through a -by-pass 44 formed in the wall of. the casing 13, and the amount of gas thus by-passedmay be regulated by an adjustable regulatlng screw 45 threaded through the wall of the duct and adapted to cooperate with a plug 46 threaded through 4the opposite wall. The regulating screw 45 is adjusted so that the gas delivered through this by-pass will enter in just` the'requislte proportions with respect to the air admitted through the orifice 11 to produce a mixture of the desired proportions. If,- therefore, the valve 17 should be fully shut of, there will still be delivered ,saddest gas through` the by-'pass44 and air throughsthe orifice 11 i to produce a mixture of the requisite proportions and in suiiicient quantities to be discharged through the conduite at`sufiicientvelocity to supply the minimum requirements of the burners without permitting a the orifice 11 is adapted to deliver under.

high pressure 180 feet of air, and the regulating screw 45 is adjusted so that 30 feet of gas will be delivered through 'the bypass. lVhen the valve 17 is entirely shut ott',

a mixture of air and gas from the orifice 1l and'the by-pass 44 will be delivered to the conduit 6 in al ratio of six to one, producing a combustible mixture of the proper proportions and of the proper quantity for turn-down purposes. lVhen more fuel is required the valve 17 may be opened, admitting the requisite additional amount of air and gas in the proper proportions. Different grades of gas will-,of course, necessitate different proportions than those mentionedwhich are merely illustrative. f

It will be apparent from theforegoing that I have provided a mixer, providing two independent sources ofL air andvgas supply, the primary mixture employed for. turndown purposes being composed of high pressure` air from the pipe 9 and the requisite.

amountof gas from the by-pass 44, and the supplemental mixture being furnished 'in desired amounts by manipulating the valve- 17. A mixture of the desired proportions, therefore, will always be furnished forv every condition of use, and the device may be operated and regulated from the single control 'lever since 'the primary mixture, once the regulating screw 45 has been set, need not be thereafter adjusted. The quantity of mixture, ranging from the minimum turn-down to the maximum capacity of the burners, may

, be regulated by simply manipulating the handle 26 and the mixture will always. be delivered by4 my device in lthe proper proportions and under the requisite pressure under all conditions. The details of construction, illustrated and described may 'obviously be varied Within Wide limits Without invention departing from the essence of the as defined in the following claims.

I claim:

1. In a fuelmixer, 'the combination of a fuel mixture delivery conduit, a manually controlled valve 'for delivering to saidconduit desired quantities of air and gas in predetermined proportions, means for deflivering air underpressure i'ntoisaidvconduit, and l means independent from said valve for delivering gas in .quantities proportional to the air delivered under pressure.

2-.' In a fuel mixer, the combination of' a fuel mixture conduit, means for delivering gas and air in predetermined proportions and in regulatablequantities to said conduit, means for delivering air under relatively high pressure' to lsaid conduit, and a' bypass through wliichgas is delivered'in prcdetermined proportions in respect to said high pressure air.

3. In a fuel mixer, the combination of a mixture delivery conduit, a manually conti'olled proportional mixing valve for de livering air and gas in predetermined proportions to said conduit, and-means, including a gas by'pass and a high pressure'air delivery device for delivering, a predeter mined quantity of air under pressure and' gasin predetermined proportions, to saidconduit vwhen said valve is closed. y l

4. In a fuell mixer, the combination of a valve casing, a mixture delivery conduit co'nnectedtherewith, aV manually controlled proportional mixing valve in said casing for delivering'air and gas to said conduit in pi'e-l determined proportions, a by-pass for deliver-ing gas independently-of said valvc,- and a high pressure air pipe adapted to dcliver into said conduit. t i t 5. A fuel mixer,"comprising a rotatable i valve providedwith air andgas inlet ports,

said air inlet port being of diminshe, l (liineiisions at one side when fully .opened means for delivering gas to-saidgas inf. let port; and adjustable 'incans 'effective at a plurality of positions of said valve for admitting` additional air through said valve.

6. A fuel mixer, comprising a valve casing having a gas port-,an adjustable gas duct, an airport, anda plurality of adjustable air du cts,'and a rotatable proportional mixing valve liavingna gas port'i'eg' isterable with said gas port of said casing and a plurality of air ports registerable with said air port and said air ductsjof said casing.

7; In va' vfuel mixer, the combination of afvalve casing, a proportional mixingvalve mounted therein provided with 'air and gas inlet p orts, a gas by-pass around said valve', means for controlling the effective area of said by-pass, air inlet ducts through said casing wall, means for controllingthe effective area' of said ducts, aiid means independent of said air inlet port for supplying air under high pressure.

that the speed of the mixture formed thereto s aid conduit to form a combustible turn down mixture delivered ata speed greater than the rate of iame propagation thereof, and means for further delivering to said conduit at will and in regulated quantities supplemental to and for admixture with said ,turn down mixture a mixture of fuel and air in predetermined proportions suitable for Working purposes.

10. The combination With a mixture conduit, of means for delivering to said conduit a combustible mixture of fuel/and air, the air leing delivered under such pressure from is greater than the rate offlame propagation of said mixture, said fuel delivery being indu-ced by said air pressure and manually controlled means for delivering to said conduit in regulated quantities a supplemental mixture of lair and fuel in predetermined proportion.

l1. A fuel mixer, comprising a casing provided with air and gas inlet ports, a valve rotatably mounted therein and provided witli ports adapted to register with the -casing ports, said casing being also provided With a plurality of auxiliary air inlet ducts and the valve'being provided with an auxiliary 1port adapted to register successively witsaid ducts upon rotative movement of the valve, desired ones of said ducts may be closed whereby to regulate the supply of auxiliary air.

and means whereby,

12. In a fuel mixer, incombinatiom' a ing valve is closed as a turn.a down m1xture the speed of which is greater than the- -rate of flame propagation thereof. l

13. In a fuel mixer, in combination, a fuel mixture delivery conduit, means for continuously delivering air and gas 1n predetermined proportions to saidconduit to form a combustible turn down mixture'delvered at a speed greater than the rate of flame propagation thereof, and a manually controlled proportional mixing valve for delivering to said conduit supplemental to.

and for admixture with said turn down mixture, air and gas in predetermined proportions suitable for Working purposes.

l-l. In combination, a source of gas supply, a fuel delivery conduit, means for delivering high pressure air into said conduit, a proportional mixing valve connecting said gas supply and operable for delivering gas and air in predetermined proportions to said conduit, and a by-pass betweensaid gas supply and conduit whereby When said valve is closed gas will be delivered to said conduit in such proportion of said high pressure air as to form a combustible turn down mixture the delivery of which is at a speed greater than the rate offlame propagation thereof.

GARNET W. MGKEE.

conduitand having a valve 

